Mercury-vapor apparatus.



P. H. THOMAS.

MERCURY VAPOR APPARATUS.

APPLICATION FILED NOV-28. 1913- 1 ,1 88,578. Patented June 27, 1916.

. WITNESSES n INVENTUR BY W UNITED STATES PATENT OFFICE.

PERCY .H. THOMAS, I F UPPER MONTCLAIR; New JERSEY; ASVSI GNOR "r0COOPER. newrr'e E' mrmc 'coMrA I-Y, or HOBOKEN, NEW JERSEY, Aconromrrrouor NEW JERSEY.

Specification of iletters Patent.

' MERciIRY-VAPOR APPARATUS.

Patented June 27, .1916.

Original application filed l fo vember 24, 1911, Serial Ne 662,131Divided and this ap plication file in' l 28, 1913. Serial No. 803,421. I

'1 gall whom it may concern Be it known that I, PERCY HQ Tiroims, acitizen of thellnited States, andresident of li'pper B'lm itclai rcounty ot-Fsseit, State of New .Terse have invented certain new anduseful Improvements in Mercury-Vapor specification.

'.\ pparati.is, ofwhich the folldwin'g 15 a- 01' for ether usefulagencies. "In some instances, hnwever' my invention may be applied tootherm'ediathanme wry;

It has been shown by eter Cooper Hewitt, and otherspfor example in anun1- her at patents issued t,0;He\\-'1 tt, that eurrent centinneusindirection and at low volt-.

age can he. made to t-raye'r an exhausted 'tzfillfztll'ltl lei-ring;suitable ele odes. therein, PIQVIflCd meansare applied for:- nvercomingthe' natural reluctance tie-"startingexlisting in suelr'apparatus. "In'a' device of this character there is a loss of voltage. and(lQVPlOPmCHt. 'of heat-at each of the elee-' trodes, the vintage lessbeing approximately.

ennstant, andfurther there is a \ffiPOllZlllllOIl or dissipation ofc0inln ;ti n; material at the urface. of the cathode. There is also aloss of voltage suffered by the current in travvifiing thespaee betweenthe electrodes wi less ufn nltage' depends very particularly upnn tiedimensions and (lisposition ut the exhausted space, the eharaeter of theDuring thepperatiun of: such a device, in

view (if the 'heat generateih the teni aa-z iture V of a solid eleetrudewill rise. until, lay ra- (liatiun and hr rnnreetien frmu the vaporpation (If heal equals the mile of: generation thereuf'. In the ease ofa liquid electrode, lmwerel, the grn i'atimi (it heat will tend to raisehutthis will autmnalir-allv cause an evapm l'llzllun.

- 0r vapor therein andthe pressure or the (we;wratiire at the electrodefrtim the liquid since the liquid is' in a closed space andthe vaporpressure therein must he that of the saturation presi at its surface,the saturation pressure of the p vapor at this point, Yi-ill helessfa'nd a'portiou I My !|1.\ftlltl0ll relates to me eury vaperapparatus such asmay he fqun useful for a production (if light, of ultraviolet rays,.

of the vapor will be condensed iintil the pressure at this point beappropriatefiothe 60 saturation pressure at thellowerztemperature. Thisproduces a difference in the pressure between the vapor near the liquidelectrode and the pressure;-at'the-eeelIpeint of the container, pausinga fl0iv.-of -'V 1ip0'r '5 and tilt era'perizatipn of; additional -vap irf-lQ fl-t-he liquid 'electroch in p'repertieirte the amuunt witl'idra\\fi 1.- 'Tlnils' there will be a emitiuueus \'apbr ization andcondensa. tiun of the vapor fronif th'e 'liitjnidelectrede at the coolspet in the "eoi 'rtainerso 'lo'ng as the-difi'ereneein temperature ismaintained. This process will proceed" very rapidly unless there -hevphysical obstructimr-in the-path of the loving "apor;

thusimpeding its progress and causing-a" permanent (hfi'erenee 1n, thepressure lie tween the two peints 'in the Container;

In a certain form of'practlcal lamp of the 7 type deseril'ied 'liyHewitt, above referred to,

the apparatus is so propertioned as to keep the.- pressure of the vaporrelatively low,

thus permitting aj relative-small lUSS (it. Voltage in the tulle and a.wide. distribution (it the. current flew. -'rlhis eonditien can hesecured only h maintaining the n ereury ;athn(le at or near a certaindefinite temperature whirh will ordinarily .llC confined in the generalueighlmrheml of the boiling [mint ul water. In some ether foruisi oflamp a higher pressure Of the mercury vaper. where niereury isthematerial used, is desirable. This is ohtained by using a (litferentprnportiun (it parts or a higher cur--- rent. so that thetemperature ofthe chic-'95 lrmle will he higher than in the former type. ln this classof apparatus the pres sure. of the mercury apor is sulliciently high tocentine the flow of. current between the eleetrmlcs to a relativelynarrow space, 1

usually to a space much smaller than the diameter of the container. Inthis case it is found that the temperature in the path traversed by thecurrent may be very high. With such devices the containers have fre'quently been made of quartz. in a re-vitritied more or less transparentform, with the resultant advantage that higher temperatures can beattained thancould be conveniently secured with ordinary glass. However,it may be noted that as the current path becomes hot as a result of theincreased pressure or density within the container that it becomesfeasible to maintain the surface of the tube'much cooler than thetemperature of the vapor in the current tion resembling that foundsuitable for a lower pressure type of lamp. I secure this result bydisposing the necessary cooling surface largely near the current path,thus permitting a relatively large diameter of container and arelatively wide separation in location between the current path and theglass wall. I find that while the current may flow near the surface ofthe glass, at or near the elcctrodes.'that the temperature of the glassis maintained within a reasonable limit nevertheless; perhaps by adispersing of heat along the glass wall to the neighboring electrode,

My inventioncontemplates means for controlling the distribution ofmercury or other liquid in a vapor electric device so that a permanentapportioning of the mercury between the various points'or the confiningof 3 the mercury at a predetermined point may be secured with the objectof preventing the formation of drops of liquid which might fall upon ahot portion of the container and cause a momentary excessive pressure ofvapor or other irregularities which appear to occur sometimes in variousforms of vapor electric apparatus, in the absence of protective means.

I will describe the invention more particularly in the form set forth inthe accompanying drawings in which l igures 1 and 2 represent a lampadapted material which constitute the electrodes, here shown as mercury;leadin wires of the usual form are shown at 4 and I provide a throat 6in immediate proximity to the electrode 3. This throat, being narrowlyrestricted, will become heated producing a spot of high temperature atthe point 7. If the level of the material of the electrode 3 isrelatively low the cooling surface of this electrode is su ient to causea condensation thereon with a consequent filling up of the electrodechamber. However, as the level of the electrode material reaches thehighly heated point 7,there is a tendency for more rapid evaporation ofthe electrode material which produces a balance between heat generatedand; heat dissipated and maintains the electrode in equilibrium. In thisdevice the bulb 8 acts as a condensing chamber for the lamp.

In Fig. 2 I show artube somewhat similar to Fig. 1', having a condensingchamber vertically over the electrode 3. The electrode 3 has arelatively small surface exposed to the vapor at 9 with the result thatthe current path at this point has little opportunity to flicker. Thesame arrangement as here shown in connection with, the electrode 3, the

condensing chamber 8 and the throat 10 may current path by the dottedlines marked 11. "hile I have shown particular embodi-- ments of myinvention in the drawings-of this application. I do not wish to limitmyself to these particular forms, for my invention is broad enough tocover any structures which bring about the same results as thoseattained herein by substantially equivalent means or arrangements.Neither'do I limit myself to any one particular vapor pressure, for anydesired pressure may be utilized within the practical limits of theapparatus, determined either by the matter of temperature, lightdensity, efliciency, temperature or other conditions, i

This application is a division of my application Serial Number (362,131,filed November 24th, 1911. 1

I claim as my invention:

1. Means for regulating the distribution of electrode material in amercury vapor tube, said mercury vapor tube including a mercuryelectrode, means for replenishing the liquid in said electrode, saidmeans havmg a capacity somewhat in excess of the natural rate ofdiminution of the electrode and additional means capable of causing a.local development of heat, said last named means being locatedat thenormal operating.

2. A vapor tube for a vapor filectr'ic appw mtus comprising a containerexhzm =1 in 2 high gig-gran of 3101111111. eieshn liquid nmierial, anelectrode at one (and of said tube pl mnuiu Eng-in Wire. mums for000M125 and a narrow wnstrictinn in tube as or near the normal lewi in"tzw .1 h'wiie n'mterin m. the 9rd! filwtxfude gm iv:- 16 'wheweh v ahigghiy hentmi '.s'tim1 of suiu e31

